NEAR MSI Albedo Mosaics
This download consists of 14 Eros global albedo mosaics across 7 filters and 2 map projections (Simple Cylindrical and Sinusoidal). The data is hosted as GeoTiffs with PDS4 and ISIS3 detached labels. A full description of the data is available in the download and the ancillary PDF.
New data
Recently, MSI data has been archived (DOI: 10.17189/sv8w-5125) with a new deblurring method applied (Golish et al., 2023). This method uses the same mathematical foundation as the original, but develops new blur models and processes the images to avoid edge-artifacts from the Fourier transforms. The new data has improved qualitative sharpness for all filters, particularly those at extreme wavelengths. With this new data, we generate global albedo maps for Eros in each of MSI’s seven filters. To enable color analyses (e.g., color ratios, band depths), we create albedo maps which are corrected to 0 degrees phase (0 deg incidence, 0 deg emission) with per-filter photometric models, rather than 30/30/0 angles used for the existing published basemaps.
Shape model
The shape model used to control and project the images for mosaicking is publicly available (Gaskell, 2020) at the Planetary Data System Small Bodies Node (PDS SBN). The shape model was created from 21,135 MSI images consisting of 1,579,014 vertices and 3,145,728 plates with an average resolution of 27 meters. The model contains 9,443,000 voxels with 75,554 coarse voxels.
- filter 1, 550 nm
- filter 2, 450 nm
- filter 3, 760 nm
- filter 4, 950 nm
- filter 5, 900 nm
- filter 6, 1000 nm
- filter 7, 1050 nm
Backgroud:
The Near Earth Asteroid Rendezvous (NEAR) – Shoemaker spacecraft observed asteroid 433 Eros for approximately 1 year in 2000 and 2001. While in a series of orbits (with distances to surface varying from hundreds to tens of km), NEAR’s Multispectral Imager (MSI) acquired over 100,000 images with of the surface in all seven of its narrowband chromatic filters. The majority of these images were acquired with the 950 nm filter, but enough were acquired in all filters to image most of the asteroid surface. Creating global mosaics with these images is challenging for two reasons. First, Eros’s extremely irregular shape made imaging under consistent conditions infeasible. The surface was heterogeneously imaged with different resolutions and photometric conditions. Moreover, the irregular shape makes image registration (both image to image and image to shape model) more difficult. It is correspondingly difficult to map the shape to any common map projections. Second, a failed burn before entering orbit deposited hydrazine fuel on the outer surface of the MSI, causing significant blurring of all surface-resolved images. The MSI team, during mission operations, developed an effective deblurring technique that they applied to all images (Li et al., 2002). The technique struggled with the highest and lowest wavelengths, but worked well in the middle of the MSI bandpass. As such, most images were acquired with the central filter (950 nm) and much of the Eros surface science was done at this wavelength. Accordingly, the two existing published basemaps of the Eros surface (Bussey et al., 2002) were generated using 950 nm images.
References:
Golish, D.R., DellaGiustina, D.N., Becker, K.J., Bennett, C.A., Robinson, M., Crombie, M.K., 2023. Blur remediation in NEAR MSI images. Icarus 400, 115536. https://doi.org/10.1016/j.icarus.2023.115536.
Bussey, D.B.J., Robinson, M.S., Edwards, K., Thomas, P.C., Joseph, J., Murchie, S., Veverka, J., Harch, A.P., 2002. 433 Eros Global Basemap from NEAR Shoemaker MSI Images. Icarus 155, 38–50.https://doi.org/10.1006/icar.2001.6771.
Gaskell, R.W., 2020. Gaskell Eros Shape Model V1.0, urn:nasa:pds:gaskell.ast-eros.shape-model::1.0 [WWW Document]. NASA Planetary Data System. URL https://doi.org/10.26033/0hpf-4e64.
Li, H., Robinson, M.S., Murchie, S., 2002. Preliminary Remediation of Scattered Light in NEAR MSI Images. Icarus 155, 244–252. https://doi.org/10.1006/icar.2001.6745.
- Publisher
- Lunar and Planetary Laboratory, University of Arizona
- Publication Date
- 16 June 2023
- Originator
- Golish, D.R., Brodbeck, J.I., Webber, C., Becker, K.J., Bennett, C.A., DellaGiustina, D.N.
- Group
- PDS
- Added to Astropedia
- 16 June 2023
- Modified
- 10 January 2024
General
- Purpose
Build global maps of Eros in the 7 available filters taken by MSI.
- Geospatial Data Presentation Form
- Global Mosaic, Image, Raster Data, Remote-sensing Data
- Online Linkage
- https://asc-pds-individual-investigations.s3.us-west-2.amazonaws.com/eros_global-albedo-maps_golish_2023/eros_global-albedo-maps_golish_2023.zip
- Native Data Set Environment
- ISIS v3
- Color
- Black and White
- Supplemental Information
- https://astrogeology.usgs.gov/search/map/Eros/MSI/NEAR_MSI_Deblurred_Images, https://doi.org/10.17189/sv8w-5125, https://doi.org/10.1016/j.icarus.2023.115536
Keywords
- System
- Small Bodies
- Target
- Eros
- Theme
- Asteroids, Cartography, Geophysical, Image Processing, Photogrammetry, Remote Sensing
- Mission
- NEAR
- Mission Specific
- Multispectral Imager (MSI)
- Search Terms
- Eros, Asteroids, Image processing
Contact and Distribution
- Access Constraints
- None
- Use Constraints
- Please cite authors
Data Status and Quality
- Time Period of Content Begin
- 12 January 2000
- Time Period of Content End
- 6 February 2001
- Currentness Reference
- Ground condition
- Progress
- Complete
- Update Frequency
- None planned
- Logical Consistency Report
- We used published photogrammetric control networks to register the images to each other and to the Eros shape model (Gaskell, 2020). The shape model itself is generated from the same control network. The control network includes all images for all filters used in the mosaics. We analyzed the quality of the published control networks to determine the resulting accuracy of the mosaics. The analysis used simulated images (generated with the published shape model and control networks) with MSI images. Control points were identified and compared in both sets of images to determine the offset between the two. All control points were merged into a large dataframe producing 789, 634 ground control points. Aggregate data for each image was generated for the plots provided below. The vast majority of the data were registered to within 2-3 pixels. The mosaics were generated at 10 m/pixel, therefore the average surface misregistration is between 10 and 30 meters.
- Completeness Report
The MSI dataset at Eros is large and heterogeneous. While the vast majority of images were acquired with filter 4, each filter has at least a few hundred to a few thousand images. We used a Postgres SQL database to filter the images and extract lists according to a variety of metrics.
- Process Description
also see Golish, D.R., DellaGiustina, D.N., Becker, K.J., Bennett, C.A., Robinson, M., Crombie, M.K., 2023. Blur remediation in NEAR MSI images. Icarus 400, 115536. https://doi.org/10.1016/j.icarus.2023.115536
Lineage
- PDS Status
- PDS 4 Like
- Source Originator
- PDS Small Body Node
- Source Publication Date
- 16 June 2023
- Source Title
- Near Earth Asteroid Rendezvous (NEAR) Data Archive
- Source Online Linkage
- https://pds-smallbodies.astro.umd.edu/data_sb/missions/near/index.shtml
- Type of Source Media
- Online
Geospatial Information
- Minimum Latitude
- -90
- Maximum Latitude
- 90
- Minimum Longitude
- 0
- Maximum Longitude
- 360
- Direct Spatial Reference Method
- Raster
- Object Type
- Pixel
- Lines (pixels)
- 5341
- Samples (pixels)
- 10682
- Bit Type
- 32
- Radius A
- 17000
- Radius C
- 17000
- Bands
- 1
- Pixel Resolution (meters/pixel)
- 10
- Scale (pixels/degree)
- 29.67
- Horizontal Coordinate System Units
- Meters
- Map Projection Name
- Simple Cylindrical
- Latitude Type
- Planetocentric
- Longitude Direction
- Positive East
- Longitude Domain
- 0 to 360